nRF5340 behavior when input voltage jumps

[Michael Zeng]

We're designing a custom PCB and plan to use the nRF5340 in high voltage mode.

The PCB accepts two different power inputs; one feeds a single cell Lipo into the VDDH pin of the nRF5340; the other feeds a regulated 3.3V to the VDDH pin. The two voltage sources are connected using reverse polarity protection diodes like so (VDD_nRF will be connected to the nRF5340's VDDH pin):

When switching power sources (for example, if a 4.2V battery were suddenly connected while V_USB is also being supplied), would this impact the nRF5340's performance at all? Is it possible that this would cause some glitches?

Thanks,

Michael

[Raoul]

Hi Michael,

The PCB accepts two different power inputs; one feeds a single cell Lipo into the VDDH pin of the nRF5340; the other feeds a regulated 3.3V to the VDDH pin. The two voltage sources are connected using reverse polarity protection diodes like so (VDD_nRF will be connected to the nRF5340's VDDH pin):

This should be okay, and it actually relieves you from having to reset the device when switching between VDD and VDDH input.

When switching power sources (for example, if a 4.2V battery were suddenly connected while V_USB is also being supplied), would this impact the nRF5340's performance at all? Is it possible that this would cause some glitches?

This should be fine too, there should be no glitching.

Best regards,

Raoul

[Raoul]

Hi again,

I want to add, just in case you're not aware, that we offer schematic reviews for our customers. So when you are done with your PCB design, feel free to share it for review (you can create a private ticket to keep your design confidential).

Best regards,

Raoul